1. Field
Provided are a chemically modified targeting protein, a pharmaceutical composition for drug delivery including the chemically modified targeting protein, and a conjugate of the chemically modified targeting protein and a drug.
2. Description of the Related Art
Low molecular drugs, in particular low molecular protein drugs, have short half-lives and short administration intervals; thus, if they are cytotoxic and non-specifically uptaken, the cytotoxicity may affect normal tissues.
To solve these problems due to the non-specific uptake, a targeting protein-drug conjugate (e.g., antibody-drug conjugate; ADC), where a targeting protein such as an antibody and a drug are conjugated, has been developed.
However, there are still remained several problems such as decrease in stability due to formation of aggregation between drugs, non-specific uptake due to external exposure of a drug, short half-life in a living body, low intracellular delivery efficiency, and the like.
Therefore, it is required to improve the stability of a targeting protein-drug conjugate, its half-life in a living body, and efficacy thereof.